How Can Vendors Of Outdoor Audio Speakers Enhance The Noise Functionality?

It is easy to be puzzled by the language which wireless speaker makers utilize to express the performance of their models. I am going to clarify the meaning of one usually used parameter: “signal-to-noise ratio” in order to help you make an informed decision whilst buying a brand new a couple of cordless loudspeakers. Once you have selected a number of cordless loudspeakers, it’s time to explore some of the specifications in more detail in order to help you narrow down your search to one model. The signal-to-noise ratio is a fairly essential specification and describes how much noise or hiss the cordless loudspeaker creates. A way to do a straightforward check of the noise performance of a pair of wireless speakers is to short circuit the transmitter audio input and then to crank up the wireless loudspeaker to its utmost. Next listen to the speaker. The static which you hear is produced by the wireless loudspeaker itself. Ensure that the gain of each set of cordless speakers is set to the same level. Otherwise you will not be able to objectively evaluate the amount of hiss between several models. The general rule is: the lower the level of hiss which you hear the better the noise performance.

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While looking at the cordless loudspeaker spec sheet, you want to look for a couple of cordless loudspeaker with a high signal-to-noise ratio figure which suggests that the wireless speakers output a small amount of noise. One of the reasons why cordless speakers create noise is the fact that they use components like transistors as well as resistors which by nature generate noise. The overall noise is dependent on how much noise every component generates. However, the location of those elements is also essential. Elements which are part of the loudspeaker built-in amplifier input stage will usually contribute most of the noise. The wireless transmission itself also will cause static which is most noticable with products which utilize FM transmission at 900 MHz. FM transmitters are quite prone to cordless interference which is why newer models typically employ digital audio broadcast. The signal-to-noise ratio of digital transmitters is independent from the distance of the wireless speakers from Amphony Inc.. It is determined by how the audio signal is sampled. In addition, the quality of components inside the transmitter will affect the signal-to-noise ratio. The majority of of latest wireless speaker use amps which are based on a digital switching topology. These amplifiers are called “class-D” or “class-T” amps. Switching amplifiers include a power stage which is constantly switched at a frequency of approximately 400 kHz. This switching frequency is also hiss that is part of the amplified signal. On the other hand, latest wireless loudspeakerspecs normally only consider the hiss between 20 Hz and 20 kHz.

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The signal-to-noise ratio is measured by inputting a 1 kHz test signal 60 dB below the full scale and measuring the noise floor of the signal generated by the built-in amp. The volume of the wireless speaker is couple such that the full output wattage of the built-in amp can be realized. Subsequently the noise-floor energy is measured in the frequency range between 20 Hz and 20 kHz and compared with the full scale signal energy. Often you will discover the expression “dBA” or “a-weighted” in your cordless loudspeaker spec sheet. A weighting is a method of expressing the noise floor in a more subjective fashion. This method was developed with the knowledge that human hearing perceives noise at different frequencies differently. Human hearing is most sensitive to signals around 1 kHz. On the other hand, signals under 50 Hz and higher than 13 kHz are hardly noticed. An A-weighted signal-to-noise ratio weighs the noise floor in accordance to the human hearing and is generally higher than the unweighted signal-to-noise ratio.

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Can The Audio Distortion Of Wireless Music Speakers Be Lowered?

Are you looking to get a couple of cordless speakers? You might be perplexed by all of the technical jargon used by makers to publish the quality of their models. I am going to highlight one frequently utilized term which, though, ist often misunderstood: “total harmonic distortion” or “THD”.

It is often hard to pick a suitable set of wireless loudspeakers due to the great amount of products. Aside from looks, you will often be faced with having to study a few of the technical specs. Total harmonic distortion is generally not very well understood. Then again, this term is nonetheless vital in terms of determining the performance of a particular type. Different terms, such as “output power” or “frequency response” are generally easier understood. Briefly, “harmonic distortion” shows how much the audio signal is being degraded as a result of the speaker or in other words how much the signal deviates from the original signal. There are two common ways in order to articulate harmonic distortion, either in percent (%) or in decibel (dB). A -20 dB or 10% distortion means that one 10th of the radiated audio is a consequence of distortion as -40 dB or 1% would mean that one percent of the energy are harmonic products of the original audio. On the other hand, be careful since there are in fact several components that cause harmonic distortion. Cordless speakers and any sort of active speaker or active subwoofer all have built-in power amplifiers to drive the speaker element. Amplifier distortion generally is dependent on the amplifier output power and is now and then shown for a few output power levels.

Distortion ratings for different output power levels are normally provided for several power levels or as a diagram listing distortion versus output power. Both of these methods allow to better evaluate the quality of the amp.Usually distortion is measured with a 1 kHz test tone. This makes it possible for evaluating equipment from different suppliers. However, distortion normally varies with different frequencies. A lot of digital amps will display increasing distortion amid higher frequency which cannot easily be uncovered through looking at the specification sheet.

Distortion is furthermore induced by the loudspeaker driver itself. The majority of loudspeakers use a driver which carries a coil. This voicecoil is placed in a magnetic field. The coil will track the magnetic field which is controlled by the audio signal to move the diaphragm. However, this movement is not entirely linear. As such the result is distortion caused by the speaker element. Most vendors are going to display harmonic distortion based on the power level as generally the higher the loudspeaker is driven the bigger the level of distortion.

The overall distortion of the speaker thus is the total of the amp distortion as well as the loudspeaker element distortion. Moreover, there are other contributing factors. Depending on the material used to construct the speaker enclosure, there are going to be vibrations or box resonances. These usually depend on the sound pressure level, the box shape, the enclosure material in addition to audio frequency. Consequently additional audio distortion will be brought about by the box itself.

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The total distortion of the loudspeaker is commonly determined by a measurement that comprises a low-distortion audio generator along with a microphone which is connected to an audio analyzer. The audio analyzer will calculate the amount of higher harmonics and compare these with the main signal to compute the distortion. Intermodulation distortion analysis is one more method that offers a better picture of the loudspeaker distortion performance with real-world signals through utilizing a test signal with two harmonics and measuring how many harmonics at other frequencies are produced by the loudspeaker.

Furthermore, please understand that most wireless speakers from Amphony are going to experience signal distortion during the audio transmission itself. This is for the most part the case for transmitters which employ analog or FM type transmission. More sophisticated types employ digital audio transmission. Typically these transmitters work at 2.4 GHz or 5.8 GHz.

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Do Digital Cordless Outdoor Speakers Provide A Lower Sound Distortion As Compared With Analogue Speakers?

I am going to provide a number of pointers to help you when looking for wireless speaker products to steer clear of any unpleasant surprises. It is tempting to think about the freedom that wireless loudspeakers promise and the comfort of adding audio anywhere in your home. Wireless speakers require power to drive the speaker elements and normally come with a power cord that has to be plugged into an outlet. This means that those speakers can only be put in locations that have power. This generally is not much of a predicament if you plan on putting loudspeakers in a different room of your house. Yet, to eradicate the power cable, some wireless speakers are powered by internal rechargeable batteries. The disadvantage is that after each use these have to be recharged. Furthermore, a number of models are rather heavy making it hard to move them around. Batteries also tend to age and need to be switched every so often.

The next thing to look at is the speaker structure and output power. If you are preparation to set up the speaker in your kitchen, you obviously won’t require as much power as installing a pair of loudspeakers as cordless surround sound speakers in your home theater. It is also essential to contemplate the sort of material of the loudspeaker housing. If you are preparing to use the loudspeakers outdoors, be sure you select loudspeakers with a rainproof housing. The material would in a lot of cases by some type of plastic. Ensure to check with the manufacturer to ensure the loudspeaker which you are preparing to buy is appropriate for outdoor use. Next, ensure that the transmitter provides the right audio inputs for your audio equipment. Firstly check which kind of audio outputs are available. Next confirm that your transmitter can connect correctly. Evidently if the transmitter offers more than just one type of input, you will have greater flexibility in case your audio equipment changes down the road. If you want to attach your transmitter to your surround system, you may require speaker terminal inputs unless your surround equipment offers line level audio for your rear loudspeakers (Visit the homepage regarding outdoor loudspeakers). Whilst nearly every transmitter has a regular line-level audio input, some also have an iPod cradle that also allows an iPhone to be plugged into. Every audio device will output audio at different audio levels. To accomodate all devices, the transmitter ought to be able to adjust its audio input level. This will stay away from clipping of the audio and take full advantage of the audio fidelity of the wireless transmission.

While historically wireless loudspeakers would employ analog audio transmission, typically at 900 MHz, the most modern generation utilizes digital audio transmission at 2.4 GHz or 5.8 GHz and eradicate audio distortion and noise. An additional benefit of digital transmission is the higher robustness against interference from other transmitters such as cordless telephones that is key with the ever growing range of wireless gizmos today. If possible, attempt to arrange a listening test. Be aware though that the sound quality also depends on your listening environment. Several cordless speakers have adjustable trebble or base. If you cannot part with your existing speakers or cannot spot a cordless loudspeaker that sounds just right, you may go with a wireless loudspeaker kit. These kits come with a transmitter and one or several wireless receivers. These receivers incorporate an audio amplifier and can attach straight to your existing speakers. Furthermore, stop by http://forums.macrumors.com/showthread.php?t=1496069&page=22.

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A Glimpse At Bluetooth Audio Receivers

Nowadays many people have got a cellphone. The majority of the most modern phones can easily hold songs and also films. Typically you are going to hear the music stored on your phone through the use of a pair of earbuds. Yet, the audio quality of headphones bundled with mobile phones can be quite bad. A better choice might be to play back the songs through some stereo speakers. You may connect the smartphone to a pair of stereo speakers with a headphone cable. But, you will also find some cordless alternatives on the market for streaming songs to some stereo speakers. In this article, I am going to summarize several alternatives for cordlessly transmitting your tunes from the mobile phone to a pair of speakers.

Nearly all stereo speakers possess significantly better sound quality when compared with mini headphones and thus are usually a much better choice for enjoying tracks with your cellular phone. You will find several alternate options for streaming your songs to your speakers. Bluetooth music receivers are among the most desired options with regard to transmitting audio from a mobile phone. Most of these receivers can pick up the cordless signal from your mobile phone and retrieve the tunes. Bluetooth music transmitting is generally done by the commonly found A2DP or the more recent AptX standard protocol.

You’ll be able to attach Bluetooth music receivers to any active stereo speakers. Having said that, most loudspeakers on the market are generally passive. To connect to a passive speaker you are going to need to utilize an external power amplifier. There are also some integrated receivers/amplifiers on the market. These types of models don’t need a separate power amp and are able to attach directly to any passive loudspeakers. Bluetooth, though, offers a fairly limited wireless range of about 30 feet and hence cannot be employed for the purpose of streaming tracks to different rooms in your home. The operating range can easily change determined by your environment as well as the level of cordless interference. Bluetooth is in fact understood by lots of gadgets other than cellphones. If you want to send audio from a PC, for instance, you can also use a stereo Bluetooth receiver.

An additional option is Airplay. Airplay is an Apple specific format which allows streaming of uncompressed music. However, understand that the songs located on your cellular phone is normally compressed via the MP3 or AAC standard and hence using Airplay will not improve the audio quality. If on the other hand you have got uncompressed audio available then making use of Airplay makes a lot of sense. AptX is actually a compromise between the popular A2DP standard and Airplay. It will provide close to CD-quality music transmitting – again presuming that you have got uncompressed music available. This specific protocol is not yet understood by many mobile phones yet the newest Bluetooth receivers do offer AptX as one choice.

Rather than employing a Bluetooth audio receiver, you might want to contemplate Bluetooth wireless stereo speakers. These kinds of speakers may receive music directly from a phone without needing a standalone receiver. You may find a large number of types in the marketplace. It is always most desirable to test the stereo speakers prior to your investment. Plenty of Bluetooth speakers lack a whole lot regarding sound quality compared to a good set of regular stereo speakers. So working with a standalone Bluetooth receiver remains to be a great idea unless you need a mobile device. Also, no matter whether you decide to purchase a set of Bluetooth speakers or a Bluetooth music receiver, you really should experiment with the unit at your dealer for you to ensure it functions with your mobile phone considering the fact that the firmware of each and every cellphone differs somewhat.

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Does High Cordless Loudspeaker Power Efficiency Imply High Cost?

When you are ready to buy brand-new cordless loudspeakers, you most likely are thinking about how efficiently your cordless loudspeakers operate. Let me reveal precisely what the term “power efficiency” means and why you must take a closer look at this number during your selection of brand new wireless speaker systems.

The less efficient your wireless loudspeakers are, the more power is going to be squandered which results in a number of complications: Low-efficiency cordless speakers will waste a certain amount of energy as heat and therefore are more costly to run in comparison with high-efficiency types due to their larger energy usage. To shield the circuit elements, low-efficiency cordless speakers need to find solutions to remove the heat that’s produced. Normally extra elements have to be added to radiate sufficient power and preserve the ideal running temperature. These components are typically heat sinks as well as fans. Heat sinks as well as fans are heavy, consume room and also produce noise. Low-efficiency wireless speakers additionally require a good amount of circulation around the wireless loudspeakers. Consequently they can’t be put in close spaces or inside air-tight enclosures. Wireless loudspeakers with small efficiency require a larger power supply in order to output the same amount of music power as high-efficiency products. An elevated level of heat triggers additional stress on elements. The life expectancy of the cordless speakers can be lowered and reliability might be compromised. High-efficiency wireless loudspeakers in contrast tend not to experience these problems and may be constructed really small.

The efficiency is shown as a percentage in the wireless loudspeakers data sheet. Various amplifier architectures deliver different power efficiencies. Class-A amps are usually the least efficient and Class-D the most efficient. Normal power efficiencies vary from 25% to 98%. Getting an amplifier with an efficiency of 90% as an example shows that 10% of the power that is used is wasted while 90% can be audio power. Please be aware, however, that efficiency depends upon just how much power the amp provides at a given moment. Amplifiers possess larger efficiency when supplying higher output power than when running at low power mainly because of the fixed energy that they consume regardless of the output power. The efficiency figure in the amp data sheet is normally provided for the highest amplifier output power. To be able to determine the power efficiency, typically a test tone of 1 kHz is fed into the amplifier and a power resistor connected to the amplifier output to emulate the loudspeaker load. Then the amplifier output signal is measured and the wattage calculated which the amplifier provides to the load which is next divided by the overall energy the amplifier consumes. Generally a complete power report is plotted to show the dependency of the efficiency on the output power. Because of this the output power is swept through various values. The power efficiency at each value is measured plus a power efficiency graph generated.

While switching (Class-D) amps possess among the highest power efficiency, they have a tendency to have higher music distortion than analog audio amplifiers and lower signal-to-noise ratio. Hence you are going to have to weigh the size of the wireless speakers against the audio fidelity. However, the newest wireless loudspeakers that use switching-mode music amps, similar to Class-T amplifiers, offer music fidelity that comes close to that of low-efficiency analog amps and can be manufactured extra small and light.

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An In-Depth Look At Current Wireless Speaker Products

Wireless audio is becoming popular. Numerous consumer products including loudspeakers which are cordless are eliminating the cable and also promise greatest freedom of movement. I am going to examine how most up-to-date wireless technology are able to address interference from other transmitters and exactly how well they will work in a real-world situation.

The most common frequency bands which might be utilized by cordless gadgets include the 900 MHz, 2.4 GHz and 5.8 Gigahertz frequency band. Mainly the 900 MHz and 2.4 GHz frequency bands have started to become clogged by the increasing number of gizmos like wireless speakers, cordless telephones and so on.

FM type sound transmitters are typically the least reliable when it comes to tolerating interference since the transmission doesn’t have any method to deal with competing transmitters. Nonetheless, these kinds of transmitters have a relatively restricted bandwidth and changing channels can often avoid interference. Digital sound transmission is frequently utilized by more sophisticated audio systems. Digital transmitters generally function at 2.4 Gigahertz or 5.8 GHz. The signal bandwidth is higher than 900 MHz transmitters and thus competition in these frequency bands is high.

Frequency hopping systems, however, are going to still cause problems as they are going to disrupt even transmitters employing transmit channels. Audio can be regarded as a real-time protocol. Because of this it has stringent needs regarding reliability. Also, small latency is vital in most applications. Consequently more advanced means are required to ensure reliability.

One method is named FEC or forward error correction. This technique allows the receiver to fix a corrupted signal. For this purpose, supplemental data is sent by the transmitter. Because of this added information, the receiver may recover the original information whether or not the signal was corrupted to a certain degree. Transmitters using FEC on its own usually may transmit to any number of wireless receivers. This approach is typically employed for products in which the receiver cannot resend information to the transmitter or in which the number of receivers is pretty big, such as digital stereos, satellite receivers and so forth.

A different technique makes use of bidirectional transmission, i.e. every receiver sends information to the transmitter. This strategy is only practical if the quantity of receivers is small. Furthermore, it needs a back channel to the transmitter. The information that is transmit has a checksum. Using this checksum the receiver may detect whether any specific packet was received properly and acknowledge. In cases of dropped packets, the receiver will alert the transmitter and the lost packet is resent. Therefore both the transmitter and also receiver need a buffer in order to store packets. Using buffers will cause a delay or latency in the transmission. The amount of the delay is directly related to the buffer size. A bigger buffer size increases the dependability of the transmission. Having said that a large buffer can lead to a large latency that may result in issues with speakers not being in sync with the video. Products which incorporate this procedure, nevertheless, are limited to transmitting to a small number of receivers and the receivers use up more power. Often a frequency channel can become occupied by another transmitter. Ideally the transmitter can realize this fact and switch to another channel. To achieve this, several wireless speakers continually monitor which channels are available so that they can immediately switch to a clear channel. The clean channel is picked out from a list of channels which has been identified to be clean. One modern technology that utilizes this transmission protocol is named adaptive frequency hopping spread spectrum or AFHSS

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A Quick Comparison Of Stereo Amps

None of latest music systems would be achievable without the aid of recent power amps that attempt to satisfy higher and higher demands concerning power and music fidelity. There is a large amount of amplifier designs and types. All of these vary when it comes to performance. I will explain a few of the most popular amp terms such as “class-A”, “class-D” and “t amps” to help you figure out which of these amps is ideal for your application. Additionally, after understanding this guide you should be able to understand the amplifier specifications that suppliers issue.

The basic operating principle of an audio amp is rather simple. An audio amp is going to take a low-level music signal. This signal usually comes from a source with a fairly high impedance. It subsequently translates this signal into a large-level signal. This large-level signal can also drive speakers with low impedance. As a way to do that, an amp uses one or several elements which are controlled by the low-power signal to make a large-power signal. These elements range from tubes, bipolar transistors to FET transistors. Tube amplifiers were frequently used a couple of decades ago and employ a vacuum tube which controls a high-voltage signal in accordance to a low-voltage control signal. One problem with tubes is that they are not extremely linear whilst amplifying signals. Aside from the original music, there are going to be overtones or higher harmonics present in the amplified signal. Thus tube amplifiers have fairly high distortion. Many people prefer tube amplifiers because these higher harmonics are regularly perceived as the tube amplifier sounding “warm” or “pleasant”.

A downside of tube amplifiers is their low power efficiency. In other words, most of the energy consumed by the amplifier is wasted as heat as opposed to being converted into audio. For that reason tube amplifiers are going to run hot and need adequate cooling. Tube amplifiers, however, a rather costly to make and consequently tube amplifiers have by and large been replaced with amps using transistor elements which are less costly to produce. Solid-state amplifiers make use of a semiconductor element, like a bipolar transistor or FET as opposed to the tube and the earliest kind is generally known as “class-A” amps. In class-A amps a transistor controls the current flow according to a small-level signal. Some amps use a feedback mechanism in order to reduce the harmonic distortion. In terms of harmonic distortion, class-A amplifiers rank highest amid all types of music amplifiers. These amps also typically exhibit very low noise. As such class-A amplifiers are perfect for quite demanding applications in which low distortion and low noise are important. Class-A amps, on the other hand, waste the majority of the power as heat. Therefore they typically have large heat sinks and are fairly heavy. To improve on the low efficiency of class-A amplifiers, class-AB amps employ a number of transistors that each amplify a distinct area, each of which being more efficient than class-A amplifiers. The higher efficiency of class-AB amplifiers also has two other benefits. First of all, the necessary number of heat sinking is reduced. For that reason class-AB amps can be made lighter and smaller. For that reason, class-AB amps can be made cheaper than class-A amps. Nonetheless, this architecture adds some non-linearity or distortion in the area where the signal switches between those regions. As such class-AB amps normally have higher distortion than class-A amps. Class-D amps are able to achieve power efficiencies above 90% by employing a switching transistor which is continuously being switched on and off and thus the transistor itself does not dissipate any heat. The switching transistor is being controlled by a pulse-width modulator. The switched large-level signal has to be lowpass filtered to remove the switching signal and recover the audio signal. Both the pulse-width modulator and the transistor have non-linearities that result in class-D amplifiers having larger audio distortion than other types of amplifiers.

New amplifiers include internal audio feedback in order to minimize the amount of audio distortion. One type of mini stereo amps which utilizes this kind of feedback is known as “class-T” or “t amplifier”. Class-T amplifiers feed back the high-level switching signal to the audio signal processor for comparison. These amps have small audio distortion and can be manufactured extremely small.

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